I've heard that for guys frequent masturbation is supposed to reduce the risk of prostate cancers and testicular cancers, because it helps to "keep the pipes clean and the supply fresh" it sounds like it makes sense but idk if it is actually true or not.

I don't know about the "as often as possible" part, but I'd say it's healthy to masturbate "as often as you want to".
It's healthy in that it can relax us without sleeping pills, calm us without anti-anxiety pills, and give us couch potatoes a few minutes of "intense cardio" every day without going to the gym or playing sports.